2 Samuel 3:26-28 New Revised Standard Version, Anglicised (NRSVA)
26 When Joab came out from David’s presence, he sent messengers after Abner, and they brought him back from the cistern of Sirah; but David did not know about it. 27 When Abner returned to Hebron, Joab took him aside in the gateway to speak with him privately, and there he stabbed him in the stomach. So he died for shedding[a] the blood of Asahel, Joab’s[b] brother. 28 Afterwards, when David heard of it, he said, ‘I and my kingdom are for ever guiltless before the Lord for the blood of Abner son of Ner.